DE69421863T2 - Thermoplastic resin composition - Google Patents

Description

The present invention relates to a thermoplastic resin composition with improved stability of the polyphenylene ether resin during processing.

Polyphenylene ether resins are superior to thermoplastic resins in various properties such as mechanical properties, heat resistance and dimensional stability. However, they may be subject to coloring and deterioration such as cross-linking when processed at high temperatures. Particularly, in the presence of oxygen, they undergo considerable deterioration due to heat, causing gelation or sometimes generating black spots. In addition, a polyphenylene ether resin is easily subject to discoloration when exposed to light.

In order to prevent these defects of the resin, it has been proposed to add various additives. For example, phosphorus additives were proposed in Japanese Patent Kokoku No. 44-29751 and phenolic additives were proposed in Japanese Patent Kokoku No. 46-24782. In addition, many attempts such as the use of various compounds including hindered amines or the use of compounds including hindered amines and phenolic additives in combination have been made mainly for inhibiting discoloration in light, as disclosed in Japanese Patent Kokai Nos. 60-149646 and 60-203150, U.S. Patent Nos. 4232131, 4233410, 4233412, 4234699, 4260689, 4260691 and 4299926, EP0094048A2, EP0134523A1, EP0146879A2, EP0146878A2, EP0151961A1, EP0149454A2, EP0233153A2, EP0240723A2, EP0229363A2 and EP0313118A1. Many of these attempts have been made to improve evaporation during processing or actual use and various compounds containing sterically hindered amines alone or copolymers (oligomers) with other components have been proposed. However, none of these proposals has provided sufficient effects to inhibit depreciation upon heating.

The present invention relates to a composition in which the deterioration of the polyphenylene ether during processing, especially under heat, is prevented.

The inventors have found that a significant effect of inhibiting heat deterioration can be obtained by adding a compound containing hindered amines having a certain structure to polyphenylene ether resins.

The present invention relates to a thermoplastic resin composition comprising (a) 100 parts by weight of a polyphenylene ether resin and (b) 0.001-15 parts by weight of at least one 4-amino-2,2,6,6-tetramethylpiperidyl compound represented by the following formula (I) or (II):

wherein R₁ represents a hydrogen atom, an oxygen atom (oxy radical), a hydroxyl group, an alkyl, cycloalkyl, allyl, benzyl, aryl, alkanoyl, alkenoyl, alkyloxy or cycloalkyloxy radical;

R₂ is a hydrogen atom, an alkyl radical or

means in which

X represents a direct bond, -O- or -NH-, R₄ represents a direct bond, a linear or branched alkylene radical, an alkylidene or arylene radical, R₅ represents a hydrogen atom, an alkyl, aryl radical,

or

means;

n is an integer from 1 to 4;

p is an integer from 2 to 6; and

(1) when n is 1, R₃ is a hydrogen atom, an alkyl, cycloalkyl, alkenyl, benzyl, aryl radical, or

wherein Y represents a direct bond, -O- or -NR₈-, and R₆ represents a direct bond, a linear or branched alkylene, alkylidene or arylene radical, and R₇ and R₈ each represent a hydrogen atom, a hydroxy group, an alkyl, aryl radical,

or

mean,

(2) when n is 2, R₃ is an alkylene radical or

where R9 represents a direct bond, a linear or branched alkylene, alkylidene or arylene radical;

(3) when n is 3, R₃ is a radical of the following formula:

means; and

(4) when n is 4, R₃ is a radical of the following formula:

or

means.

Fig. 1 is a graph showing the change of kneading torque with time in Example 1.

Fig. 2 is a graph showing the change in torque during kneading in Comparative Example 1.

The polyphenylene ether resin (a) is a polymer obtained by oxidation polymerization of at least one phenol compound represented by the following formula with oxygen or a gas containing oxygen using an oxidation coupling catalyst:

wherein R₁₀, R₁₁, R₁₂, R₁₃ and R₁₄ each represent a hydrogen atom, a halogen atom or a substituted or unsubstituted hydrocarbon radical and at least one of the symbols represents a hydrogen atom.

Examples of R₁₀, R₁₁, R₁₂, R₁₃ and R₁₄ are hydrogen, chlorine, bromine, fluorine, iodine, a methyl, ethyl, n- or iso-propyl, n-, sec- or t-butyl, chloroethyl, hydroxyethyl, phenylethyl, benzyl, hydroxymethyl, carboxyethyl, methoxycarbonylethyl, cyanoethyl, phenyl, chlorophenyl, methylphenyl, dimethylphenyl, ethylphenyl and allyl group.

Examples of the compounds represented by the above formula are phenol, o-, m- or p-cresol, 2,6-, 2,5-, 2,4- or 3,5-dimethylphenol, 2-methyl-6- phenylphenol, 2,6-diphenylphenol, 2,6-diethylphenol, 2-methyl-6-ethylphenol, 2,3,5-, 2,3,6- or 2,4,6-trimethylphenol, 3-methyl-6-t-butylphenol, thymol and 2-methyl-6- allylphenol.

The phenolic compounds of the above formula can also be copolymerized with other phenolic compounds, for example aromatic polyol compounds such as bisphenol A, tetrabromobisphenol A, resorcinol, hydroquinone and novolak resins.

As preferred examples of the polyphenylene ether resin (a), there may be mentioned homopolymers of 2,6-dimethylphenol, homopolymers of 2,6-diphenylphenol, copolymers of a major amount of 2,6-dimethylphenol and a minor amount of 3-methyl-6-t-butylphenol or 2,3,6-trimethylphenol.

Any oxidation coupling catalyst can be used for the oxidation polymerization of the phenol compound, provided it is capable of polymerization.

The 4-amino-2,2,6,6-tetramethylpiperidyl compound (b) having a sterically hindered amino group as a skeleton is represented by the following formula (I) or (II):

wherein R₁, R₂, n, p and R₃ are as defined above.

Preferred examples of the 4-amino-2,2,6,6-tetramethylpiperidyl compounds are given below.

[I] Compounds represented by formula (I) or (II) wherein n is 1 and R₃ is a hydrogen atom, an alkyl, cycloalkyl, alkenyl, benzyl, aryl or

where Y is a direct bond, -O- or -NR�8-,

and R₆ represents a direct bond, a linear or branched alkylene radical, an alkylidene or arylene radical, and R₇ and R₈ each represent a hydrogen atom, a hydroxyl group, an alkyl, aryl radical,

or

mean.

More preferred examples are compounds represented by formula (I) or (II) wherein R₂ represents a hydrogen atom or an alkyl group and R₃ represents a hydrogen atom, an alkyl, cycloalkyl, alkenyl group or

wherein Y represents a direct bond, -O- or -NR₈- and R₆ represents a direct bond, a linear or branched alkylene radical having 1-10 carbon atoms, an alkylidene or arylene radical, and R₇ and R₈ each represent a hydrogen atom, a hydroxyl group, an alkyl radical having 1-18 carbon atoms, an aryl radical having 6-21 carbon atoms,

or

mean.

Examples of the connections are given below.

4-Amino-2,2,6,6,-tetramethylpiperidine, 4-methylamino-2,2,6,6-tetramethyl-4-piperidine, 4-ethylamino-2,2,6,6-tetramethylpiperidine, 4-propylamino -2,2,6,6-tetramethylpiperidine, 4-butylamino-2,2,6,6-tetramethylpiperidine, 4-hexylamino-2,2,6,6-tetramethylpiperidine, 4-octylamino-2,2,6,6 -tetramethylpiperidine, 4-dodecanylamino-2,2,6,6-tetramethylpiperidine, 4-diethylamino-2,2,6,6-tetramethylpiperidine, N-(2,2,6,6-tetramethyl-4-piperidyl)-piperidine , N-(2,2,6,6-tetramethyl-4-piperidyl)acetamide and N-(1,2,2,6,6-pentamethyl-4-piperidyl)stearoylamide.

In addition, the compounds represented by the structural formulas below can be mentioned.

[2] At least one of the 4-amino-2,2,6,6-tetramethylpiperidyl compounds represented by the formula (I) or (II) wherein n is 2 and R₃ is an alkylene group or

where R�9 is a direct bond, a linear or branched alkylene radical, an alkylidene or arylene radical or R₃ is

wherein R₉ represents a direct bond, a linear or branched alkylene radical, an alkylidene or arylene radical, and more preferably R₉ represents a direct bond, a linear or branched alkylene radical having 1-10 carbon atoms, an alkylidene or arylene radical, such as ethylene, 1,2-, 1,3- or 1,4-propylene, 1,2-, 1,3- or 1,4-butylene, pentamethylene, 2,2-dimethyl-1,3-propylene, hexamethylene, octamethylene, cyclohexylene and cyclohexylenedimethylene. Typical examples of the compounds are the compounds having the following structural formulas

More preferred are the compounds represented by formula (I) or (II) wherein when R₃ represents an alkylene radical, R₁ represents a hydrogen atom, an oxygen atom (oxy radical), a hydroxyl group, an alkyl, cycloalkyl, allyl, benzyl, aryl, alkanoyl, alkenoyl, alkyloxy or cycloalkyloxy radical and R₂ represents a hydrogen atom or

where X is a direct bond,

-O- or -NH-, R₄ is a direct bond, a linear or branched alkylene radical, an alkylidene or arylene radical, R₅ is a hydrogen atom, an alkyl, aryl radical,

or

means.

When R2 represents a hydrogen atom, R1 is preferably a hydrogen atom, a hydroxyl group, an alkyl group having 1-10 carbon atoms or an alkyloxy group having 1-10 carbon atoms, more preferably a hydrogen atom or a methyl group. As typical examples of the compounds, there may be mentioned N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexanediamine, N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)ethylenediamine, N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,4-butanediamine and N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,8-octanediamine.

Compounds represented by the formulas wherein R₁ is a hydrogen atom or a methyl group and R₂ is a hexamethylene group are preferred, and of these compounds, N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexanediamine is particularly preferred.

When R₂ represents an alkyl group, R₁ may, for example, represent a hydrogen atom, a hydroxyl group, an alkyl group having 1-10 carbon atoms such as a methyl, ethyl or propyl group, or an alkyloxy group having 1-10 carbon atoms and furthermore, when the number of carbon atoms is 3 or more, may include cyclic groups such as cyclohexylmethyl and cyclohexylethyl, other than linear or branched groups. R₁ preferably represents a hydrogen atom or a methyl group, R₃ is preferably an alkylene radical having 2-8 carbon atoms and includes alkylene radicals represented by -CnH2n-, such as ethylene, 1,2- or 1,3-propylene, 1,2-, 1,3- or 1,4-butylene, pentamethylene, 2,2-dimethyl-1,3-propylene, hexamethylene, octamethylene, cyclohexylene and cyclohexylenedimethylene.

R₂ preferably represents an alkyl group having 1-18 carbon atoms or an alkyloxy group having 1-18 carbon atoms. Examples are a methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, sec-butyl, n-pentyl, n-hexyl, 2-ethylhexyl, n-octyl, 1,1,3,3-tetramethylbutyl, n-decyl, n-dodecyl, n-octadecyl, cyclohexyl, 3,3,5-trimethylcyclohexyl, cyclooctyl and cyclodecyl group.

If R&sub2; for

where X is a direct bond, -O- or -NH-, R₄ is a direct bond, a linear or branched alkylene radical, an alkylidene or arylene radical, R₅ is a hydrogen atom, an alkyl, aryl radical,

or

R₁ may represent, for example, a hydrogen atom, a hydroxyl group, an alkyl group having 1-10 carbon atoms such as methyl, ethyl and propyl group, or an alkyloxy group having 1-10 carbon atoms, and may further include, when the number of carbon atoms is 3 or more, cyclic groups such as cyclohexylmethyl and cyclohexylethyl, other than the linear or branched groups. R₁ preferably represents a hydrogen atom or a methyl group.

R₃ preferably represents an alkylene group having 2-8 carbon atoms and includes alkylene groups represented by -CnH2n- such as ethylene, 1,2- or 1,3-propylene, 1,2-, 1,3- or 1,4-butylene, pentamethylene, 2,2-dimethyl-1,3-propylene, hexamethylene, octamethylene, cyclohexylene and cyclohexylenedimethylene.

R₃ preferably represents a hydrogen atom or an alkyl group having 1-18 carbon atoms. Examples of the alkyl group are a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, sec-butyl group, n-pentyl group, n-hexyl group, 2-ethylhexyl group, n-octyl group, 1,1,3,3-tetramethylbutyl group, n-decyl group, n-dodecyl group, n-octadecyl group, cyclohexyl group, 3,3,5-trimethylcyclohexyl group, cyclooctyl group and cyclodecyl group.

R₃ preferably represents a hexamethylene group having 6 carbon atoms.

[3] At least one 4-amino-2,2,6,6-tetramethylpiperidyl compound represented by formula (I) or (II) wherein n is 3 and R₃ is

means.

Examples are given by the structural formulas below.

[4] At least one 4-amino-2,2,6,6-tetramethylpiperidyl compound represented by formula (I) or (II) wherein n is 4 and R₃ is

or

means.

Examples are given by the structural formulas below.

The amount of the component (b) is 0.001-15 parts by weight, preferably 0.1-10 parts by weight, based on 100 parts by weight of the polyphenylene ether resin. If it is less than 0.001 part by weight, no gelling inhibition effect is observed, and if it is more than 15 parts by weight, problems such as foaming during actual use due to volatile components occur.

The thermoplastic resin composition of the present invention is obtained by mixing the component (a) and the component (b) by conventional methods and melt-kneading the mixture. The component (b) may be added during the polymerization of the component (a).

The thermoplastic resin composition of the present invention can be molded by various methods such as injection molding, blow molding, sheet molding, film molding and vacuum molding. Blow molding, sheet molding and film molding are most suitable because the composition is highly protected from degradation by heat. The molded articles obtained can be widely used as packaging materials, household appliances and exterior and interior equipment parts for automobiles.

The present invention is explained in detail by the following non-limiting examples. In the examples and comparative examples, polyphenylene ether and additives are kneaded at 300°C for 30 minutes by a small kneader for batch kneading at 90 rpm, and the change in torque is examined. As polyphenylene ether melted, torque decreased, and then gelation occurred by crosslinking, causing deterioration of polyphenylene ether, and torque increased greatly. As deterioration further progressed, the melting state changed to a powdery state, causing a decrease in torque.

The following starting materials were prepared to prepare the compositions in the Examples and Comparative Examples.

(Polyphenylene ether resin PPE):

A polyphenylene ether obtained by homopolymerization of 2,6-dimethylphenol having an inherent viscosity of 0.46 when measured at 30ºC in a chloroform solution (concentration: 0.5 g/dl).

(Additives): Additive 1: Sanol LS-770 (manufactured by Sankyo Co., Ltd.) Additive 2: Tinuvin 622 (manufactured by Ciba-Geigy Corp.) Additive 3: Chimasorb 944 (manufactured by Ciba-Geigy Corp.) Additive 4: Adekastab PEP-36 (manufactured by Asahi Denka Kogyo KK)

Reference examples

Preparation examples of the compounds used in the examples are given below. In the examples, % means wt% unless otherwise stated.

Manufacturing example 1

Preparation of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexanediamine (Compound 1):

In a 5 liter autoclave were placed 981 g (6.32 mol) of 2,2,6,6-tetramethyl-4-piperidone, 350 g (3.01 mol) of hexamethylenediamine, 1500 g of methanol and 5.0 g of 5% platinum on carbon, keeping the temperature at 45-55ºC. The interior of the autoclave was pressurized with hydrogen to 40 bar and heated to 70-80ºC, while carrying out hydrogenation. Hydrogenation was completed after 4-5 hours. The catalyst was removed by filtration at 70-80ºC under 2-3 bar and 1070 g of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexanediamine were obtained by distillation. Yield: 90%

Boiling point: 188-190ºC / 0.80 millibar

Manufacturing example 2

Preparation of N,N'-bis(2-methoxycarbonylethyl)-N,N'-bis(2,2,6,6-tetramethyl-4- piperidyl)-1,6-hexanediamine (compound 2):

In a 1 liter 4-neck flask, 80 g (0.20 mol) of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexanediamine and 200 g of methanol were placed and the mixture was completely dissolved. To this was added dropwise at room temperature a solution prepared by dissolving 35 g (0.41 mol) of methyl acrylate in 100 g of methanol. The reaction was then carried out under reflux for 12 hours. After completion of the reaction, the solvent was distilled off and the residue was purified from hexane. recrystallized to give 98 g (0.17 mol) of the desired compound 2 as a white solid. Yield: 85%.

Melting point: 50-52ºC.

Manufacturing example 3

Preparation of N,N'-bis(2-octadecyloxycarbonylethyl)-N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexanediamine (Compound 3):

In a 4-neck flask equipped with a stirrer and a reflux condenser, 20 g (35 mmol) of N,N'-bis(2-methoxycarbonylethyl)-N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexanediamine (Compound 2) obtained in Preparation Example 2, 21 g (77 mmol) of stearyl alcohol and 200 ml of toluene were charged and then stirred under reflux. To this was added dropwise a solution of 0.1 g (4 mmol) of lithium amide in 3 g of methanol. Then the solvent was distilled off with addition of toluene and the reaction was terminated. After 4 hours of reaction, toluene was added and then cooled to room temperature. The organic layer was washed three times with water and then concentrated to give 23 g (22 mmol) of the desired compound 3. Yield: 63%.

Melting point: 45-46ºC.

Manufacturing example 4

Preparation of N,N'-bis(2-t-butoxycarbonylethyl)-N,N'-bis(2,2,6,6-tetramethyl-4- piperidyl)-1,6-hexanediamine (Compound 4):

The procedure of Preparation Example 3 was repeated except that t-butyl alcohol was used as a starting material to obtain 13 g of the desired compound 4.

Melting point: 72-73ºC.

Manufacturing example 5

Preparation of N,N'-diacetyl-N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexanediamine (compound 5):

In a 300 ml 4-neck flask, 20.7 g (50.7 mmol) of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexanediamine and 70 g of pyridine were charged and the mixture was completely dissolved. To this, 11.64 g (0.114 mol) of acetic anhydride was added dropwise over 30 minutes and then stirred at 40°C for 1 hour. After cooling, 100 g of a 20% aqueous NaOH solution and 50 ml of toluene were added and the product was extracted and washed with 50 ml of water. The solvent The residue in the toluene layer was distilled off and the residue was recrystallized from 20 ml of n-hexane to give 20.6 g of the desired compound 5. Yield: 85%.

Melting point: 152-154ºC.

Manufacturing example 6

Preparation of N,N'-bis(n-hexylcarbonyl)-N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexanediamine (Compound 6):

The procedure of Preparation Example 5 was repeated except that heptyl anhydride was used instead of acetic anhydride to obtain 18.8 g of the desired compound 6.

Melting point: 123-125ºC.

Manufacturing example 7

Preparation of N,N'-bis(ethoxycarbonyl)-N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexanediamine (Compound 7):

To a solution of 39.4 g (0.1 mol) of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)- 1,6-hexanediamine in 200 ml of 1,2-dichloroethane cooled to -10°C was added 22.8 g (0.21 mol) of ethyl chlorocarbonate at a temperature of 0°C or lower. Then 8.4 g of sodium hydroxide dissolved in 50 ml of water was slowly added thereto while maintaining the temperature at 0°C. The temperature was then raised to 20°C, the aqueous layer was separated, the organic layer was washed with water and dried over anhydrous sodium sulfate to remove the solvent. Then the residue was crystallized from octane to obtain 44.1 g of the desired compound 7. Yield: 82%.

Melting point: 125ºC. Preparation Example 8 Preparation of compound 8:

In a 4-neck flask equipped with a thermometer, a stirrer and a reflux condenser, 156 g of 4-amino-2,2,6,6-tetramethylpiperidine, 400 ml of toluene and 98 g of maleic anhydride were charged, the atmosphere in the flask was replaced with nitrogen, and then stirred at 60 °C for 6 hours. After completion of the reaction, the white crystals produced were filtered and washed with toluene to obtain 243 g of the desired compound 8.

Manufacturing example 9 Preparation of compound 9:

Commercially available 2,2,6,6-tetramethyl-4-piperidylamine was used.

Manufacturing example 10

Preparation of methyl 2,2,6,6-tetramethyl-4-piperidylaminopropionate (compound 10):

7.8 g (0.05 mol) of 2,2,6,6-tetramethyl-4-piperidine and 5.6 g (0.065 mol) of methyl acrylate were reacted in 50 g of methanol for 3 hours under reflux.

The solvent was distilled off to obtain 8.0 g of a colorless liquid of methyl 2,2,6,6-tetramethyl-4-piperidylaminopropionate as a fraction of 130-136 °C / 1.5 mmHg. Preparation Example 11 Preparation of compound 11:

In a 4-neck flask equipped with a thermometer and a stirrer, 156 g of 4-amino-2,2,6,6-tetramethylpiperidine, 32 g of acetone, 239 g of chloroform and 0.4 g of benzyltrimethylammonium chloride were charged and the mixture was cooled to 5°C with stirring. To this was then added dropwise 257.6 g of a 50% aqueous potassium hydroxide solution over 1 hour while maintaining the internal temperature at 5-10°C and then the reaction was allowed to proceed at 0-10°C for 5 hours.

After completion of the reaction, the aqueous layer was separated and removed. The excess chloroform in the organic layer was distilled off to obtain 176 g of white crystals. Yield: 92.6%. Melting point: 127-128°C. A parent peak 380 was confirmed by FD mass spectrometry. Preparation Example 12 Preparation of compound 12 having the following structural formula:

In a 4-neck flask equipped with a thermometer and a stirrer, 156 g of 4-amino-2,2,6,6-tetramethylpiperidine, 400 ml of toluene and 121 g of triethylamine were charged, and the atmosphere in the flask was replaced with nitrogen. After cooling the contents to 0°C, 119 g of sebacic acid chloride was added dropwise thereto with stirring while maintaining the internal temperature at 0-5°C. After completion of the addition, 200 ml of a 20% aqueous sodium hydroxide solution was added to dissolve triethylamine hydrochloride produced by the reaction. After separating and removing the aqueous layer, the residue was washed with 100 ml of water. The organic layer was concentrated and the residue was crystallized from n-hexane to obtain 203 g of white crystals. Preparation Example 13 Preparation of compound 13 having the following structural formula:

Tris(2,3-epoxypropyl)isocyanurate (29.7 g, 0.1 mol) and 4-amino-2,2,6,6-tetramethylpiperidine (47.5 g, 0.3 mol) were slowly heated in a hot bath with stirring. Heating was carried out to about 80°C: the temperature was raised to 100 ± 5°C and maintained for about 2 hours. After cooling, a white powder of tris[2-hydroxy-3-(2,2,6,6-tetramethyl-4-piperidylamino)propyl]isocyanurate (74.5 g) was obtained. Yield: 97.4%.

Melting point: 55-60ºC.

example 1

3 parts by weight of compound 1 were added to 100 parts by weight of PPE and the mixture was kneaded discontinuously for 30 minutes at 300°C and 90 rpm by a small kneader. The change in torque is shown in Fig. 1. It can be seen that even after 30 minutes, no visible increase in torque due to gelation was observed.

Comparison example 1

Only 100 parts of PPE were kneaded by a small kneader for 30 minutes discontinuously at 300ºC and 90 rpm. The change in torque is shown in Fig. 2. After 16 minutes, a visible increase in torque was observed due to gelation. The time before visible gelation occurs (the time required for the torque to increase by 40% from the lowest value of torque) is hereinafter referred to as the gelation time.

Examples 2-14 and comparative examples 2-5

The additives added, their amounts and the gelation time are given in Table 1.

From the above examples and comparative examples, it can be seen that the compounds recommended by the present invention are very effective in inhibiting the deterioration of polyphenylene ether due to the action of heat during processing. Table 1

The deterioration of polyphenylene ether caused by heat exposure during processing can be significantly inhibited by adding a certain sterically hindered piperidine compound to the polyphenylene ether.

Claims (18)

1. A thermoplastic resin composition comprising (a) 100 parts by weight of a polyphenylene ether resin and (b) 0.001-15 parts by weight of at least one 4-amino-2,2,6,6-tetramethylpiperidyl compound represented by the following formula (I) or (II): wherein R₁ represents a hydrogen atom, an oxygen atom (oxy radical), a hydroxyl group, an alkyl, cycloalkyl, allyl, benzyl, aryl, alkanoyl, alkenoyl, alkyloxy or cycloalkyloxy radical; R₂ is a hydrogen atom, an alkyl radical or means, in which X is a direct bond, -O- or -NH-, R₄ is a direct bond, a linear or branched alkylene radical, an alkylidene or arylene radical, R₅ is a hydrogen atom, an alkyl, aryl radical, or means; n is an integer from 1 to 4; p is an integer from 2 to 6; and (1) when n is 1, R₃ is a hydrogen atom, an alkyl, cycloalkyl, alkenyl, benzyl, aryl radical, or wherein Y represents a direct bond, -O- or -NR₈-, and R₆ represents a direct bond, a linear or branched alkylene, alkylidene or arylene radical, and R₇ and R₈ each represent a hydrogen atom, a hydroxyl group, an alkyl, aryl radical, or mean, (2) when n is 2, R₃ is an alkylene radical or where R�9; a direct bond, a linear or branched alkylene, alkylidene or arylene radical; (3) when n is 3, R₃ is a radical of the following formula: means; and (4) when n is 4, R₃ is a radical of the following formula: or means. 2. A thermoplastic resin composition according to claim 1, wherein component (b) is a compound of formula (I) wherein R₁ and R₂ each represents a hydrogen atom or an alkyl group having 1-8 carbon atoms, and n represents 1 or 2, and (1) when n represents 1, R₃ represents a hydrogen atom, an alkyl, cycloalkyl, alkenyl group or wherein Y represents a direct bond, -O- or -NR₈-, and R₆ represents a direct bond, a linear or branched alkylene radical having 1-10 carbon atoms, an alkylidene or arylene radical, and R₇ and R₈ each represent a hydrogen atom, a hydroxyl group, an alkyl radical having 1-18 carbon atoms, an aryl radical having 6-21 carbon atoms, or mean; and (2) when n is 2, R₃ is where R9 is a direct bond, a linear or branched alkylene radical having 1-10 carbon atoms, an alkylidene or arylene radical. 3. The thermoplastic resin composition according to claim 1, wherein at least one 4-amino-2,2,6,6-tetramethylpiperidyl compound of the component (b) is represented by the formula (I) wherein n is 2 and R₃ is an alkylene group. 4. The thermoplastic resin composition according to claim 1, wherein at least one 4-amino-2,2,6,6-tetramethylpiperidyl compound of the component (b) is represented by the formula (I) wherein n is 2, R₂ is a hydrogen atom and R₃ is an alkylene group. 5. The thermoplastic resin composition according to claim 1, wherein at least one 4-amino-2,2,6,6-tetramethylpiperidyl compound of the component (b) is represented by the formula (I) wherein n is 2, R₁ represents a hydrogen atom or a methyl group, R₂ represents a hydrogen atom and R₃ is a hexamethylene group. 6. The thermoplastic resin composition according to claim 1, wherein at least one 4-amino-2,2,6,6-tetramethylpiperidyl compound of the component (b) is represented by the formula (I) wherein n is 2, R₂ represents an alkyl group and R₃ represents an alkylene group. 7. A thermoplastic resin composition according to claim 1, wherein at least one 4-amino-2,2,6,6-tetramethylpiperidyl compound of component (b) is represented by the formula (I) wherein n is 2, R₂ is where X is a direct bond, -O- or -NH-, R₄ is a direct bond, a linear or branched alkylene, alkylidene or arylene radical, R₅ is a hydrogen atom, an alkyl, aryl radical, or and R₃ is an alkylene radical. 8. A thermoplastic resin composition comprising (a) 100 parts by weight of a polyphenylene ether resin and (b) 0.001-15 parts by weight of at least one compound represented by the following formulas (i) - (iv): wherein R₁₀ represents a hydrogen atom, a hydroxyl group, an alkyl or an alkyloxy radical, R₁₁ represents an alkylene radical, R₁₂ represents an alkyl or an alkyloxy radical, R₁₃ represents a hydrogen atom or an alkyl radical, R₁₄ represents a hydrogen atom, an oxygen atom (an oxyradical), a hydroxyl group, an alkyl, cycloalkyl, allyl, benzyl, aryl, alkanoyl, alkenoyl, alkyloxy or cycloalkyloxy radical, Z represents O or NH, and m is an integer of 1 or 2. 9. The thermoplastic resin composition according to claim 8, wherein in the formula (i), R₁₀ represents a hydrogen atom, a hydroxyl group, an alkyl group having 1-10 carbon atoms or an alkyloxy group having 1-10 carbon atoms, and R₁₁ represents an alkylene group having 2-8 carbon atoms. 10. A thermoplastic resin composition according to claim 8, wherein in the formula (i), R₁₀ represents a hydrogen atom or a methyl group, and R₁₁ is a hexamethylene group. 11. The thermoplastic resin composition according to claim 8, wherein in the formula (ii), R₁₀ represents a hydrogen atom, a hydroxyl group, an alkyl group having 1-10 carbon atoms or an alkyloxy group having 1-10 carbon atoms, R₁₁ represents an alkylene group having 2-8 carbon atoms, and R₁₂ represents an alkyl group having 1-18 carbon atoms or an alkyloxy group having 1-18 carbon atoms. 12. A thermoplastic resin composition according to claim 8, wherein in the formula (ii), R₁₀ represents a hydrogen atom or a methyl group. 13. The thermoplastic resin composition according to claim 8, wherein in the formula (iii), R₁₀ represents a hydrogen atom, a hydroxyl group, an alkyl group having 1-10 carbon atoms or an alkyloxy group having 1-10 carbon atoms, R₁₁ represents an alkylene group having 2-8 carbon atoms, R₁₂ represents an alkyl group having 1-18 carbon atoms or an alkyloxy group having 1-18 carbon atoms, and R₁₃ represents a hydrogen atom or an alkyl group having 1-18 carbon atoms. 14. A thermoplastic resin composition according to claim 8, wherein in the formula (iii), R₁₀ represents a hydrogen atom or a methyl group and m represents 2. 15. The thermoplastic resin composition according to claim 8, wherein in the formula (iv), R₁₀ represents a hydrogen atom, a hydroxyl group, an alkyl group having 1-10 carbon atoms or an alkyloxy group having 1-10 carbon atoms, R₁₁ represents an alkylene group having 2-8 carbon atoms, and R₁₄ represents a hydrogen atom, a hydroxyl group, an alkyl group having 1-10 carbon atoms or an alkyloxy group having 1-10 carbon atoms. 16. A thermoplastic resin composition according to claim 8, wherein in the formula (iv), R₁₀ represents a hydrogen atom or a methyl group, and m represents 2. 17. A thermoplastic resin composition according to claim 1, wherein the 4-amino-2,2,6,6-tetramethylpiperidyl compound is a compound of the formula where R₁ and n have the meanings given in claim 1, R₁₅ represents a hydrogen atom or an alkyl radical, and (1) when n = 1, R₁₆ is a hydrogen atom, an alkyl, cycloalkyl, alkenyl radical, preferably an allyl radical, a benzyl radical or means, wherein R₄, Y and R₈ have the same meanings as in claim 1, (2) when n = 2, R₁₆ wherein R₄ has the same meaning as in claim 1, (3) when n = 3, R₁₆ means, and (4) when n = 4, R₁₆ or is. 18. The thermoplastic resin composition according to claim 17, wherein the 4-amino-2,2,6,6-tetramethylpiperidyl compound of the formula (III) is a compound wherein R₁ represents a hydrogen atom or an alkyl group having 1-8 carbon atoms, R₁₅ represents a hydrogen atom or an alkyl group having 1-18 carbon atoms, n = 1 or 2, and if n = 1, R₁₆ is a hydrogen atom, an alkyl, cycloalkyl, alkenyl radical or means, wherein Y represents a direct bond, -O- or -NR₈-, R₄ represents a direct bond, a linear or branched alkylene radical having 1-10 carbon atoms, an alkylidene radical having 1-10 carbon atoms or an arylene radical, and R₈ independently represents a hydrogen atom, an alkyl radical having 1-18 carbon atoms, an aryl radical having 6-21 carbon atoms, or means, and if n = 2, R₁₆ has the formula means, where R4 represents a direct bond, a linear or branched alkylene radical having 1-10 carbon atoms, an alkylidene radical having 1-10 carbon atoms or an arylene radical.